How is floor leveling done with joists? Lag structures of the subfloor How to install logs by level.

Wooden flooring on joists remains one of the most popular options in private houses and old apartments. Low price, high durability and ease of work distinguishes this method of flooring from other types. If you are building a house and decide to install floor joists yourself, or you need to update old ones, this article will tell you the technology for installing them.

Floor technology on joists

If you look at the diagram of the structure of a wooden floor, you can see several basic structural elements:

• The base for installation is a concrete screed, floor slab, wooden beams, or brick columns.
• Then there are layers of waterproofing to protect against moisture from below the floor.
• The floor joists are fastened through the substrate to level the level.
• Insulation is installed between the joists on a backing made of plywood or plasterboard.
• The logs are covered with a vapor barrier membrane on top.
• The top layer is covered with floorboards.

Preparing the base

If the fastening will be on wooden beams, no additional work no need to do it. The joists are simply attached to the ends of the beams level, so there is no need for pads.

Installation of floor joists on a concrete base is done in two ways. The first is to use pads under them to install them in the same plane. The second is to pre-prepare a level base.

This can be done by spot filling uneven areas, pouring screed, or using a layer of sand.

If you are doing installation in a private house on the ground floor, then often in such houses they install it on posts, that is, the floor will go above the ground.

In this case, you will need to first pour a 20-30 cm foundation for each column on a sand base. Then a column of bricks or blocks is laid on this foundation.

They need to be laid at the same level; for this, the height of the columns is adjusted by the layer of mortar in the masonry or the height of the foundation. To increase the durability of the brick, you need to protect it from top and bottom with a layer of roofing felt waterproofing.

Before starting work, remove dirt and install waterproofing.

Calculation of pitch and lag sizes

Before purchasing materials, you need to calculate the costs and dimensions of the logs in advance. You need to buy dry timber, 2-3 grades.

Its cross-section should be rectangular, the height is approximately 2 times greater than the width. Please note that the height should be enough to lay the insulation inside and maintain a ventilation gap of 2 cm.

The longer the width of the room, the wider you need to buy logs. For example, for 3 meter room It would be optimal to take a beam of 150*80 mm, for a 5 meter beam – 200*150.

The distance between the joists will depend on the floorboard used. For example, for a 24 mm board you need to make a laying step every 40 cm, and for 40 mm you can do it every 70 cm. Most often, a step of 50 centimeters is used, because it is more convenient to lay the insulation inside exactly to size without cutting, and you get good floor rigidity .

Installation of logs

• We set the logs according to the level and place wooden choppers under them if necessary.
• Before installing the main elements, the piping is first installed around the perimeter of the room. To do this, first install logs with an indentation of 0.5-1 centimeter from the wall for a temperature gap. There should be no wedges between the wall and the beam; they will create a squeak when walking.
• Then all intermediate bars are mounted. The location of the floor joists should be perpendicular to the window so that the upper boards are secured along the direction of the light. The finishing floor covering is also laid along the light so that the gaps between the parts are not visible.

• If you need to trim each beam and join a row of several halves, then you need to move this joint each row to increase strength.

Note! The chops do not need to be rigidly attached to the floor; they are simply laid on the base. The main rule when installing is to maintain a reliable and stable fastening so that nothing dangles.

• Many people ask, is it necessary to be tough? There is no need to do this. A rigid mount will conduct vibration noise, reducing sound insulation. When walking, sounds will be transmitted through the ceilings to neighbors.
• However, it is possible to secure the logs together. This will firmly bind the entire structure, and they certainly will not move. Make crossbars from scraps of timber and secure them. Use fasteners for the floor joists - ordinary 4*4 metal corners.
• If you don’t make such a harness, then it’s okay. All the same, the structure will then be tied together after sheathing with boards.
• It is important to use only self-tapping screws during fastening. They should be long and thick enough. If you use nails or bad screws, after a short period of time the boards will begin to creak when you walk, as they become loose.

Note! The fewer parts there are in the design, the lower the likelihood of squeaking. But at the same time, it is necessary to ensure reliable fixation of the boards and rigidity of the structure so that it does not shake.

• After the installation of the floor joists is completed, underlays for insulation made of plywood or plasterboard are laid inside them. Then the insulation itself (min. wool, expanded polystyrene, sawdust) is tightly placed between the logs. The vapor barrier is secured on top of them with a stapler and the floor covering begins.

One of the main methods that can be used to make a flat floor surface is to lay boards or sheet materials onto a pre-created sheathing, where as load-bearing elements, - lags. One of the primary tasks, the implementation of which directly affects the final quality of the floor surface, is the alignment of the joists in the horizontal plane, their reliable fixation, as well as processing protective compounds and waterproofing. You can learn how to adjust the position of wooden beams, as well as some of the nuances of the process of installing a frame under a horizontal floor surface by reading this article. Thematic video lessons offered for viewing will help you consolidate the information received.

Features of the floor by joists

There was a period when from the technology of flooring to wooden blocks developers began to move away. This was due to the fact that in this way it was difficult to achieve a perfectly flat surface, which was necessary for laying modern floor coverings. Preference was given to screeds made with cement-based mortars.

Now modern technologies lumber production makes it possible to produce wood products that are distinguished by regular geometric shapes, and special impregnations make wooden beams durable and prevent their deformation. More advanced materials have appeared at a reasonable price for decking, such as plywood and OSB boards. This made it possible to return to the technology of installing floors using joists, bringing it to a higher quality level.

The widespread use of this method of constructing a floor surface is also explained by the popularization of wooden construction, when houses are built from logs or timber. In such a building, any floors other than wood would look inorganic. However, logs as a frame for flooring used not only in wooden houses. This floor leveling technology is used everywhere. In private houses, including on the second floor, in city apartments and even in office premises. Its advantages, such as, for example, will help explain the popularity of this technology:

• relatively low cost of the material/labor complex, especially when we're talking about about the installation of ceilings on the second floor of the house;
• the ability to qualitatively insulate the floor surface by laying a thick layer of insulation;
• the created surface is immediately ready for installation finishing materials(does not need drying and maturing like concrete);
• it is convenient to lay communications under the flooring;
• the frame, made of bars, as well as the flooring, have a relatively small weight, due to which the load on the floors and bearing structures decreases noticeably;
• The workflow is quite simple, making it accessible to many home craftsmen.

This floor also has some disadvantages:

• despite the use of fire retardants, wood remains a combustible material;
• the use of logs, for example, in an apartment, involves a reduction in useful volume;
• impossibility of making heated floors.

Base surfaces for installing joists

A horizontal frame made of wooden beams can be made in any room. But the base surface that serves as support for the joists is different. If the floor structure is assembled on the ground floor of a private house with a ventilated underground, as supporting elements There are columns poured with concrete or lined with brick. In apartments and some houses on the second floor, where the interfloor partition is filled with reinforced concrete slab, the latter is the basis for installing load-bearing beams. When a ground floor is made on the first floor of the house, a rough screed is prepared for installing the bars. Let's look at the installation rules and methods for aligning the load-bearing beams in each option.

Important! If the interfloor ceiling in a house is made of timber, its surface is the basis for plywood, OSB or board flooring on the second floor. The alignment of the beams occurs during the construction stage of the building.

How to align load-bearing beams on a reinforced concrete slab?

You can install logs on the slab using several devices, such as:

• screw adjustable supports;
• support brackets;
• anchor fastenings.

Screw supports and metal brackets are used when it is necessary to raise the floor surface relative to the base surface in order to lay insulation between the joists. With the help of these devices it is convenient to fasten the bars and adjust their position relative to the horizontal. Another advantage of such devices is the absence of contact between wooden beams and the concrete surface, which eliminates the need to waterproof the logs.

Anchors are used when the beam is laid directly on a concrete surface, and its position is regulated by all kinds of pads. This is done when the thickness of the thermal insulation layer is of great importance does not have, at the same time there is a desire to minimize the usable space.

To level the logs and install them in the same plane, you need to use a hydraulic level and a long (1.5-2 m) spirit level. Using a water level, marks are made on two opposite walls that correspond to the horizontal line in which the load-bearing beams should be located.

The outermost logs are installed and leveled first, which are located approximately 10 cm from the wall. First, one edge of the beam is set according to the mark that determines the desired horizontal level. Then the position of the other edge is adjusted so that the floor support is horizontal. The same should be done with the block against the other wall.

When the outer joists are set and secured in a given position, strong twines are stretched between them so that their sagging is minimal. Tensioned threads located in the same horizontal plane will serve as a guide for adjusting the position of the intermediate lags. To mark the horizontal line, if possible, you can use laser level. This will speed up the process and perhaps improve accuracy somewhat. You can see how the logs are installed on metal brackets, as well as their alignment, in the video below, which shows the entire process of installing a plywood floor base along the load-bearing beams on the loggia.

Joists on columnar supports

In this case, in order to avoid problems with the alignment of the logs, the supports for them themselves should be made so that their upper platforms are in the same plane. The principle is the same - the horizontal line is marked, in which the top points of the columns will be located and the threads are stretched. If the supports are made of reinforced concrete, the formwork elements are placed along the threads. When the columns are laid out of brick, the masonry is adjusted according to the guidelines.

The beams are installed on the made supports after laying 2-3 layers of rolled waterproofing on them and are fixed with metal angles or anchors through the joist body to the surface of the column. Load-bearing wooden crossbars are leveled by placing wooden or plastic wedges.

Important! Needs to be laid waterproofing material not only between the surface of the column and the lag, but also between the support and the ground, so that moisture does not destroy the supporting structure.

It is necessary to perform several basic tasks regarding a level and durable floor laid on joists. This is the exact alignment of the logs in one horizontal plane, their reliable fastening to the base, treatment with protective compounds, plus waterproofing of the entire structure. Before you align the logs under the wooden floor, you need to select them correctly according to their cross-section. Because this indicator affects the reliability and strength of the entire structure. If the house is undergoing renovations and the joists have already been installed, it is recommended to open the floors and check the beams for their quality condition. If necessary, some of them are replaced with new ones.

The appearance on the market of new floor coverings, which required a very flat surface when laying, was supplanted by the technology of constructing floors using joists. They were replaced by screeds filled with cement-based mortars. This simplified the process of leveling the base for finishing, but this technology also had several disadvantages. One of them was that we had to wait a long time for the screed to dry. And this could take several days.

Modern technologies for the production of lumber have brought back the method of constructing a floor using joists due to the correct geometry of the products produced, through the use of dry wood. They were helped by protective impregnations that penetrated the wood, increasing its service life and preventing deformation under load. Manufacturers, thanks to new technologies, began to produce improved inexpensive materials for flooring on joists. This is not only plywood, I would like to mention OSB boards. With the help of durable and smooth sheet and panel materials, it became possible to lay laminate, linoleum, and ceramic tiles on the floor along joists.

We must also pay tribute to the fact that wood construction has become fashionable again. Increasingly, customers give their preference to construction wooden houses. And in such houses, wooden floors look harmonious. Although logs for floor construction are used not only in wooden structures. Today they are also used in city apartments, especially on the ground floor, when the task is to insulate the floors.

But this design also has its drawbacks.

• Even wood floors treated with fire retardants are still flammable structures.
• It is not possible to install a heated floor heating system in them.
• When installing joists in apartments, be prepared for the fact that the ceiling height will decrease.

Design features of the installation

If we are talking about installing joists in a city apartment, then there is only one option for placement and alignment - laying it on a concrete floor slab, which is filled with a concrete screed on top. In principle, the result is a fairly flat surface, but 100% flatness is still a long way off. Therefore, the logs in the apartment will still have to be leveled.

In houses, floors are constructed in three ways:

1. On the ground. The upper edges of the foundation are backfilled in several layers of different materials: crushed stone, sand, clay. All this is compacted, the screed is poured on top. The logs are installed along it. As an option, the logs are leveled along the foundation and filled completely. Only their upper ends remain on the surface, to which the flooring is attached. In this case, it is better to backfill with sand, and the wooden elements must be treated with protective agents before installation.
2. On the foundation with or without support columns.
3. Along load-bearing beams.

Leveling joists in an apartment

First of all, you need to determine the highest place on the floor. Usually this is either a corner of the room or one of the edges near the wall. Therefore, we measure the height of the ceiling in each corner of the room. Smallest size– this is the necessary place. Now, from this corner to the others, a liquid building level is stretched from a transparent vinyl chloride tube, which is filled with water, and an air bubble is left inside. If the bubble rises to the designated corner when the level is set, it means that the assumptions were confirmed - this corner of the room is the highest. The same can be done with the middles of the floor edges adjacent to the wall surfaces.

• Now a log is installed on the floor, one end of which is located in the selected corner of the room. The distance from the wall is 5 cm in the middle of the longitudinal axis.
• The opposite end is raised so that a short level placed on the joist shows that the installation is even. That is, the air bubble in the chamber should stop in the middle.
• A lining, previously cut from a block or plywood, is inserted under the raised end. There can be several spacers, it all depends on the magnitude of the plane difference.
• The log stands horizontally. It can be fixed to the floor, for example, with metal corners.

Now we need to install another joist element at the opposite wall and align it horizontally and in the same plane with the already installed one. Depending on the width of the room, you can use either a flat wooden strip or a long two-meter rule for this. One end of them is installed on top of the laid log in the corner of the room. You can start from any end. The rule is set to the horizon, which will be shown by an air bubble. A log is placed under its free end, and pads are placed at the end of it. The same is done with the other end. After which the log is attached to the floor.

So, two logs are installed and secured to opposite walls. Now between them you need to stretch several threads (4-5 lines), which will indicate a horizontal plane. The threads are attached at the upper ends to nailed nails. Now intermediate logs are installed along the threads, under which pieces of plywood or wood are placed. The main requirement is that the threads must touch the upper ends of the lags.

Manufacturers today offer adjustable designs with which you can easily set the logs. These are metal or plastic devices that are attached to the floor with dowels or anchors. They are equipped with beams that can be raised or lowered using threaded connection. Using this leveling option, you do not have to carry out complex measuring operations to determine the highest point on the floor.

Instead of adjustable structures, you can use regular anchors, which are screwed at one end into the concrete base of the floor. A nut is screwed onto them and a wide washer is installed on top. A log is put on, on top of which a wide washer is installed and a nut is screwed on. Essentially, this is still the same adjustable device.

Alignment with foundation and supporting beams

The operation of leveling the logs along the foundation and along the beams is carried out in the same way. But there are also differences.

By foundation

Typically, the ends of the logs rest on the foundation, which is the basis for the floor. It is always not poured evenly, so the logs have to be placed in the same plane along the horizon. Here everything is done almost exactly the same as in the apartment.

• Two logs are installed at opposite walls.
• Each of them is leveled horizontally using a building level with pieces of plywood placed under the ends.
• Threads are stretched between their ends, which in turn are checked for drop. The joist that is higher in height will be the main one, that is, the starting point in the process of leveling all other joist elements. It must be immediately secured to the foundation and walls of the house.
• The ends of the second outermost log are placed along the stretched threads, which is also immediately secured.
• Several more threads are stretched between the bars, defining the horizontal plane. Intermediate elements of the joist structure lined with plywood or wood are placed on them.

If the distance between the edges of the foundation is large, then support columns are built between them, on which the beams rest. The main requirement for constructing supports is to accurately adjust their height so that the logs fit tightly on them. If this cannot be done as accurately as possible, then pads are placed under the bars.

Along load-bearing beams

The floor structure based on load-bearing beams is considered very reliable. Large-section beams or logs are installed on the foundation or ceiling, onto which the logs are mounted. There are two options for leveling the floor structure.

1. The beams are leveled.
2. The logs are leveled.

It is more difficult to level with logs, because this lumber is not even in cross-sectional geometry along its entire length. Therefore, craftsmen try to process the upper and lower planes with a plane to give it the appearance of a plane. In this regard, it is better to use timber, because it is a rectangular material that today manufacturers produce with precise geometry.

• First, two beams are laid on opposite sides.
• They are leveled along the horizon, supported by pieces of plywood, but preferably metal plates.
• Then they are aligned in the same plane with each other, as was described with the foundation logs. That is, the log located above is left in place. Additional metal elements are placed under the second.
• After that, intermediate beams are placed along the tensioned threads.
• And the logs are laid and fastened along the beams without leveling.

Alignment of lags along beams is carried out in the same way. This option is easier in that it will not be necessary to lift heavy logs and beams to place plates under them. First, the logs are installed across the beams. That is, the logs are mounted on a large number of supports. Secondly, the beams themselves are a reliable and durable foundation. Therefore, when choosing a cross-section of logs, you can choose beams of a small cross-section, such as those used to construct floors in apartments.

The leveling process itself is carried out exactly the same as in an apartment. There is only one deviation - the logs can be attached to the beams or with self-tapping screws directly, since both elements are wooden, or using metal corners. Otherwise, the installation technology is the same.

How to install logs Currently in construction, specialists use many methods of laying flooring. Among the most popular: installation on a clean screed, on a dry screed and laying on joists. It is the last method that is the oldest and most proven, which we will talk about in this article. Lag is the frame of the floor covering on which the finished floor is laid. The lag, as a rule, is well-dried wooden beam a length of at least 2 meters and a cross-section of at least 110x60 mm. However, in Lately builders use logs from polymer materials, which have the best performance characteristics. When installing the log in wooden house logs are often used. Log logs are laid using the same technology as structures made from other materials. When choosing a wooden material, you must pay attention to the quality of the wood: Firstly, as we said earlier, it must be dried, otherwise the wood will become deformed during use, which, in turn, can damage the floor covering. Secondly, the wood should not contain knots. In place of a knot, the log will have the least strength and there is a high risk of its destruction under load, which will lead to failures in the coating. It is advisable to treat the wood with drying oil before installation to extend its service life. Advantages and disadvantages of a floor on joists The main advantage of this floor configuration is its relative cheapness and ease of installation. In private houses, when the height of the floor above the foundation can reach several tens of millimeters, do concrete screed not entirely effective, since filling such a distance will require a large amount of filler, which is quite expensive. In addition, the use of a joist structure will allow the installation of a ventilated floor. The air layer under the floor will make it warmer due to low thermal conductivity, and will also prevent moisture from accumulating, which negatively affects the final coating. With the help of logs, you can correct any surface unevenness by leveling them. Under such a floor, you can lay a layer of insulation and soundproofing material, as well as lay communication lines. The log construction is quite durable and correct installation lasts a very long time. The disadvantages of flooring on joists are associated with the characteristics of the wood. As a rule, they appear when the installation technology or the rules for choosing bars are violated. If the cross-section of the joists is incorrectly selected, the distance between them is incorrectly calculated, or the substrate is laid in violation of the technology, such a floor will not serve for a long time. In apartments with low ceilings laying the floor on joists can reduce the volume of the room. Selecting joists for installing flooring It is best to entrust this operation to professional builders who will install the floor. However, if you are going to do this work yourself, when choosing materials you need to take into account several main conditions: Dimensions of the room. Depending on this parameter, the number of logs, their cross-section and length are selected. As a rule, the bars are placed across the room so that batten, which will be mounted on them, lay lengthwise. This way, the seam of the board will not be visible in the light from the window. Calculating the lag size is simple. To do this, we use the relationship between the size of the room's span and the dimensions of the beam. For a span of 2 meters minimum section timber will be 110x60 mm, for 3 meters - 150x80 mm, 4m - 180x100 mm, 5m - 200x150 mm, 6m - 220x180 mm. If the room falls within the borderline value, then choose a larger log size, with a margin. That is, with a span length of 5.3 meters, it is better to take a beam of 220x180 mm. Floor load. For heavily trafficked rooms, such as a corridor or kitchen, the number of joists should be greater, as well as their size. This floor is laid on hard wood that can withstand heavy loads. On the Internet you can find many videos on installing logs, which will guide you in making the right choice material. The distance between the floor joists, and, accordingly, their number is calculated depending on the thickness of the floorboard. The dependence is as follows: with a board thickness of 20 mm, the distance between the lags should not exceed 300 mm, with a thickness of 24 mm - 400 mm, 30 mm - 500 mm, 50 mm - 1000 mm. How to install logs: main points The configuration of the frame depends on the material from which the covering will be laid. If you are planning a flooring made from a solid floorboard, then the logs can only be placed in one direction. If installation is required sheet panels thick plywood, chipboard or OSB, then at the place of their joint you need to install transverse logs so that all the joints lie on them. Otherwise, the joint that “hangs in the air” will sag and, as a result of the friction of the two plates, produce a not very pleasant sound. Before installation, it is necessary to consider the waterproofing system. For this, it is better to use roofing material, rubemast or polyethylene. How to install floor joists on wooden beams In old houses with wooden floor logs are attached directly to wooden beams. Before installing the subfloor, it is necessary to assess the reliability of the beams. If they are in poor condition, measures should be taken to strengthen them. The bars are attached to the beams using screws, the diameter of which should not be less than 6 mm. Before fastening, the logs are leveled. During work, you must be extremely careful not to split the board. To do this, before tightening the screw, we drill a hole at the place of its installation with a diameter half its size. Fasteners for logs are installed in increments of 300 mm. If the beams are located at a distance greater than the thickness of the main covering allows, then the logs are laid in two layers in a cross pattern. The first layer is attached to the beams, and the second is placed on it with a smaller distance between the lags. Do-it-yourself installation of logs on a concrete base Most often, a wooden floor is installed on a concrete floor. In old houses, especially those in which the floors consist of several small concrete slabs, the floor is laid on joists. The fact is that the more joints there are between the floor slabs, the less neatly they are laid. And the slabs themselves, at the pace of construction, were not made very well, which, in turn, was corrected by laying a wooden floor. It is also worth noting that the wooden floor is on joists due to its good qualities, is often found in new buildings. Installing wooden joists on concrete is not a very complicated operation and can be done independently. An important point In the production of such work is the arrangement of waterproofing. It is needed so that the wood does not absorb moisture that comes from the concrete. If funds allow, insulation should be laid over the entire surface of the floor, but if not, under the lag substrate. Polyethylene or roofing felt can be used as waterproofing. Laying the bars is done using a level. The first two outer logs are laid at a distance of at least 50 mm from the wall. We align them by level. We adjust the height using wooden blocks and wedges. To prevent the wedges from falling out from under the joists, we sew them together with a nail on the side of the beam. We install substrates for the logs in increments of no more than 50 cm. When the outer beams are exposed, we sew them together with 2 - 3 rough boards. We place the remaining logs on these boards. After the frame is mounted, we lay a layer of thermal insulation. To do this, it is better to use mineral wool in rolls. In some cases, when the surface on which it is planned to lay the logs is too uneven, a rough screed is poured before installing the floor frame. This step will give the floor a stronger and more even base. Installing logs on the ground This installation method is most often found in private homes. First you need to prepare the soil: compact it thoroughly. To do this, you can use a large, heavy log, using it as a roller. It is recommended to make a simple tamper by welding iron handle To metal plate 20 mm thick and approximately 300 x 400 mm in size. After compacting the surface, add a small layer of 2-3 cm of expanded clay or other filler. Next, we begin pouring the foundation pillars under the logs. This operation is done in the following order: We make marks on the walls corresponding to the position of the joists. Then we retreat 20 cm from the edges of the marks and make new marks for installing the unlaces. We proceed in the same way along the other axis of the room. At the intersections of the cords we drive in pegs - they indicate the position of the corners of the pillars. Next, we remove part of the soil in the designated places, compact the hole and fill it with crushed stone, after which we compact it again. We install formwork with a height of 100-150 mm. We lay a layer of waterproofing at the bottom of the foundation pit. We reinforce the foundation with a mesh of reinforcement with a diameter of 8 mm, welded or twisted wire. The height of the reinforcement should be 50% of the height of the foundation column. We pour concrete. To do this, we use a “lean” mixture, in which there is more sand or screenings than cement. After that, let it dry for 2-3 days. After the concrete has dried, remove the formwork and place pieces of roofing felt on the posts. We lay two layers of brick, and the second layer should be located perpendicular to the direction of the log. A soundproofing pad is placed on top of the brick. We install logs. We attach them to the support posts using corners. We screw the corner to the foundation using a dowel, and to the joist using a screw.

Wooden bath floors have been used since ancient times. And today, despite the presence large quantities new technologies, this option is rightfully considered optimal. We will look at several solutions for arranging floors, talk about the technology of their construction, advantages and “problematic” aspects.

Ground logs
Making wooden floors

There is only soil under the floor joists
Logs for the floor in a log house

This means that there is nothing under the floor except soil. The logs themselves, of course, never rest on the ground or various bedding; they need to be installed on concrete or brick pillars.

Logs on brick pillars
Columns made of blocks for logs

The distance between the posts is calculated taking into account the thickness of the joists, floorboards and the maximum load on the floor. During the construction of baths, in most cases no one makes such exact calculations, and they are not needed. The average universal values ​​are selected; in our case, we choose the thickness of the floorboards 30 mm and the joists 50×100 mm.

In this option, the distance between the logs should be within 1.5 meters, the distance between the columns under each log should be within 1.6÷1.8 meters. A few centimeters in one direction or another does not make a difference; move the columns taking into account the specific dimensions of the room.

The main thing is that the columns should be evenly spaced over the entire area.

Lag pitch depending on the thickness of the floorboards
Log dimensions at a pitch of 70 centimeters

How are floors with joists on the ground made?

Step 1. Take measurements of the room and determine the floor level. Construction documentation has its own characteristics. One of them is that the zero mark does not touch the ground, as some people think, but the floor level. Everything above the floor is indicated in the drawings with a “+” sign, everything below the floor level is indicated with a “-” sign. This means that the level of the logs should be indicated as -30 mm (below the thickness of the board). One more note on the documentation. Accuracy in millimeters is indicated in mechanical engineering; in construction, dimensions are in most cases indicated in centimeters. We will gradually move to standard designations for the sizes of construction projects, but for now we will use familiar, but not entirely correct designations.

Support posts for logs on the ground - diagram
Construction of wooden floors on columns

Step 2. Taking into account the distances, pre-calculate the installation locations of the posts and their number. The depth of the columns is approximately 20÷25 centimeters.

Mark the columns. On the opposite walls of the room, use a laser or hydraulic level to mark the zero mark (the level of the upper surface of the floorboards). Subtract 30 millimeters (thickness of the boards) and 100 mm (thickness of the logs). The level of the upper surface of the column is -13 centimeters. On the walls of the bathhouse, make another mark at this height.

Along the rope at the required distances, dig small square holes of this size; the depth of the holes is enough to make one bayonet of a shovel. Level the bottom and remove any loose soil.

It is highly advisable to pour sand cushion 10÷15 centimeters thick to compensate for soil swelling during freezing/thawing. Place a layer of sand at the bottom of each hole and compact it. If you want to fill holes, make a concrete solution in the proportions of 1 part cement, 2 parts sand and 3 parts crushed stone. When pouring, make sure that the surface is smooth and horizontal.

Step 3. Prepare all materials. There are several options for posts: pour concrete into the ground or use concrete blocks. Above the ground, you can use red bricks or blocks, between concrete base and bricks must be waterproofed with roofing felt. Take better brick, his small sizes facilitate the work of bringing the columns to one level of the horizon. The blocks have to be cut, it takes a long time, the cut turns out to be uneven.

Brick support column - appearance

Step 4. Making columns. We make the dimensions of the columns to match the brick, standard length bricks 25 centimeters, take two bricks. This means that the side of the square column will be 25 centimeters.

Do you have some concrete blocks available? Great, the work will go faster and easier, lay out columns of them.

The concrete has hardened - you can lay bricks. Thickness standard brick only 6.5 centimeters, such dimensions will allow, by changing the thickness of the solution, to accurately adjust the surface of the columns to the required height. You need to tighten new ropes, pull them according to the height marks of the posts. Check the position of the bricks with a level; the posts should be in a vertical position. Using cement-sand mortar, accurately adjust the surfaces of all posts along the thread.

Step 5. The logs are laid on roofing felt; it is better to lay two layers of waterproofing.

The length of the logs should be 3–4 centimeters shorter than the length of the room, this is necessary to compensate for the expansion of the tree. The joists must be fixed to the walls in a sliding manner to prevent them from tipping to the side, but allow them to move slightly in the longitudinal direction. It is better to do this using standard factory metal connections, such as those used during the construction of a floating rafter system. If it is not possible to purchase such connections, no problem, make them yourself. To do this, the holes on one side of the metal corner need to be made oblong. This side will be attached to the joists with self-tapping screws; do not tighten the screws with great force, the joists should be able to slide. The second side of the metal corner is fixed to the wall of the bathhouse.

First you need to fix two opposite logs, pull ropes between them and lay everything else along it. If there are problems with the level, use different pads. Variation in height up to two millimeters can be allowed; these irregularities are eliminated over time finishing floor coverings.

Step 6. Laying boards. Check the quality of the boards; it is better not to use materials with visible signs of defects. If the boards have a curved side surface as a result of a violation of production technology, you need to purchase ready-made ones or make them yourself special devices to tighten them.

For these purposes, you can use ordinary metal staples and wooden wedges. Prepare several wedges at once with different slope angles. Metal brackets are driven into the joists, and between them is placed unnecessary board, and wedges are driven between the floorboard and it. The driving force should ensure leveling of the surfaces. The boards are fixed to the joists in this clamped position; after driving in all the nails, the wedges are removed and a new floorboard is inserted.

Bowrench – a tool for tightening floor boards

Do not forget to leave a gap of 1-2 centimeters wide near the wall to compensate for linear expansions; the gap is then closed with a plinth. For flooring, you can use both ordinary and tongue and groove boards. If all operations were performed correctly and the boards have no deviations in thickness, the floor is ready for final painting or varnishing. If there is a noticeable difference in the height of individual boards, then you will have to level them with a special manual jointer.

To improve the quality of the coating, the floor surface can be sanded.

Step 7 Nail the baseboards around the perimeter of the room - the floor is ready for use.

Fastening wooden skirting boards

There are two more nuances to installing floors in a steam room. The technology for laying the boards changes slightly depending on how the water will drain. If gravity flows into the cracks, do not pull the boards tightly, leave a gap of several millimeters between them.

If water goes into the drainage system, you need to make a hole. The best option- have electric jigsaw. Drill a “starting” hole in the board with a drill, insert a jigsaw knife into it and carefully cut out the hole the right size. No jigsaw - use a chisel and chisel. The work gets a little more complicated, but it's not scary. Small irregularities in the hole made in this way will be covered with a decorative drain grate.

Joists over concrete screed

A more complex and expensive flooring option. The logs are placed on a flat concrete screed; the floors can withstand significant loads.

Step 1. Mark the floor level and place marks on the wall. You need to mark both the position of the joists and the position of each layer of the cement base.

Step 2. Level the soil surface, remove the top fertile layer. You need to pour a base of sand or gravel onto the ground; compact the base using special vibration mechanisms or manually.

Example of compacting a sand cushion

Step 3. Prepare the concrete solution. When making concrete, we recommend using two parts sand and three parts crushed stone for one part of cement. This concrete recipe can be considered universal; it is suitable for the manufacture of most architectural structures of buildings using concrete.

Step 4. Pour the concrete base. You need to fill along the beacons.

For beacons, you can use purchased metal or ordinary ones. wooden slats. The slats do not need to be pulled out of the solution; they do not affect the final performance characteristics. Use a level to check the flatness of the concrete. If there are significant deviations, screed the top with cement-sand mortar. Do the screed according to all the rules, do not allow unevenness or horizontal deviations.

Prices for cement-sand mixture

cement-sand mixture

Video - Installation of beacons under the screed

Video - Beacon screed

Step 5. Between the concrete base and wooden joists install waterproofing.

If you do not plan to insulate the floor, then you can take 30x50 mm bars as joists and lay them flat. The large support area of ​​the logs completely eliminates their deflections, and the thickness is sufficient for strong fixation of the boards. The length of the log must take into account linear expansion due to changes in the relative humidity of wooden structures.

Video - How to lay joists on a concrete floor

Step 6. The boards are laid in the same way as we described above using the example of laying them along joists on the ground.

In cases of bathhouse construction, this flooring method is used infrequently. Such floors can only be made in a relaxation room; the method is not suitable for a steam room or shower. Laminate flooring or soft floor coverings are laid over plywood. The thickness of the plywood is determined by the general loads, but in any case it should be more than one centimeter. Depending on the thickness of the plywood, the pitch of the lag is adjusted. Experienced builders It is recommended to install logs at a distance of no more than 50 centimeters.

Laying plywood on joists

Plywood must be moisture resistant; ordinary cheap varieties are unsuitable.

Important. When marking the placement of logs, it is tedious to take into account the dimensions of the plywood sheets.

The fact is that there must be logs under all joints. It is better to first draw on paper a diagram of the arrangement of plywood sheets; during calculations, both longitudinal and transverse joints should be taken into account. You can fix the plywood to the joists with nails or self-tapping screws.

And, in addition, it has good heat-protective characteristics, which makes it possible not to use it for floors. additional insulation. Do not forget to glue the joints of the sheets of technical cork with tape. Otherwise, they will shift during the work, which complicates the installation of the laminate and makes the work more “nervous.”

Prices for plywood sheets

plywood sheets

Methods for insulating floors along logs in a bathhouse

Floor insulation using joists - diagram

To insulate pilaf, two types of insulation can be used. None of them are ideal option. Why?

Let's start with mineral wool.

In many performance indicators it has high performance: holds heat well, is easy to work with, the thermal insulation layer has no gaps. But cotton wool also has a drawback - the material quickly absorbs moisture and releases it for a very long time. Long stay wooden elements in direct contact with wet cotton wool, it significantly accelerates the appearance of rot and fungi. Wooden structures need to be soaked in antiseptics, use mechanical methods steam and water protection. Such construction activities are quite expensive.

The second insulation is polystyrene foam boards.

This material does not absorb moisture. The fact that there are comments about it regarding environmental friendliness is not critical for the premises in the bathhouse, no one is going to live in them. What “destroys” polystyrene foam is not its environmental friendliness and physical characteristics; it is “destroyed” by rodents.

None of the manufacturers warn that for unknown reasons mice really like this material; they chew it with great pleasure and at great speed. Completely get rid of rodents summer cottage no one has succeeded yet. We hope this information will help you decide optimal solution when choosing floor insulation material.

How to insulate floors along joists with mineral wool

You can take both rolled and pressed material. The only note is that if you take pressed mineral wool, then the dimensions of the sheets should be taken into account when placing the logs.

Nail thin slats or bars to the side planes of the logs; the subfloor will lie on them. To make it you can take unedged boards, pieces of lumber, remnants of plywood or OSB sheets. Mineral wool must be reliably protected from moisture penetration from below; the ground under the bathhouse will always have increased humidity levels.

For vapor protection, you can take any of the existing materials; they all have excellent performance characteristics.

Lay mineral wool on the subfloor carefully, do not leave any gaps or gaps. The thickness of mineral wool cannot be greater than the height of the logs.

The top surface of the insulation must be covered with waterproofing and only after that begin to work on the finishing floor covering.

One of the floor insulation options. The film is fastened with staples over basalt mineral wool

If it is possible to replace mineral wool with glass wool, take this chance immediately. Glass wool is much cheaper than “branded” material, and in terms of its physical and operational properties is in no way inferior to her.

Glass wool - insulating material

One of the disadvantages of glass wool is considered to be its “prickliness”. This is not a problem, work in canvas work gloves and nothing will “bite” you. For your information, fashionable mineral wool is made from mountain basalt, which is the same glass, only with different impurities. Mineral wool “doesn’t bite” only because the diameter of the glass fibers is much smaller, they break very easily and cannot damage the skin. But there is much more fine glass dust, and this is harmful to the lungs.

Prices for mineral wool

mineral wool

In this option, the work is slightly simplified and cheaper. The subfloor is made in a similar way as in the case of insulation mineral wool. But you don’t have to do steam and water protection; this can significantly reduce the cost of the work. You will have to solve the problem with rodents yourself. Some suggest laying galvanized metal mesh with small cells on the subfloor, while others will ensure that rodents do not spoil all the foam. You will have to decide for yourself what to do.

Polystyrene foam can be cut perfectly with a special carpenter's knife. When cutting, make the sheets a few millimeters larger. The sheet will easily shrink, due to this the tightness of the fit to the joists will significantly increase. With proper cutting, the amount of unproductive material waste is reduced, and work is completed faster and with better quality.

Prices for foam plastic

Styrofoam

Video - How to cut foam with a knife

Scheme utility networks you should have before starting the construction of floors, they need to be taken into account when marking the locations of the joists and laying insulation. Let's give a few practical advice for installation of engineering communications.

1. All connections must be made as securely as possible and very carefully. This applies to both sewer pipes, and electrical wiring.

   

2. Electrical cables must be laid in plastic or corrugated metal pipes. In fact, we do not recommend laying wiring under the floor; it is much more convenient to route it along the walls. Moreover, they will still be finished with clapboard or other materials, and under them you can hide all the networks without any problems.

   

3. For sewerage, it is necessary to provide for the most dangerous places in terms of blockages. Open pipelines in such places have special technological access; if the pipes become clogged, they can be easily cleared with their help. Most often, dirt accumulates in the knees and joints. Place them as close to the walls of the premises as possible. Moreover, the boards in such places must be parallel to the direction of the pipeline. This will make it possible, in the event of unpleasant situations, to provide access to the problem area after dismantling just one or two boards.

   
   
   

Communications under the floor

During the installation of sewer pipelines, it is better to make a reserve for throughput, to be safe from cases of clogging. The pipe path will be larger in diameter, let them total length will increase slightly. The main thing is to have confidence in long-term and reliable operation the entire system.

Video - Installation of subfloor

Video - Floors on the ground. How to do it right